Capacitor Plague for unused New In Stock boards

The conventional wisdom is that the bad capacitors (the ones with stolen chemical formula) bulged because of the hours you put in it. Today I found that it’s not true. I had a batch of new old stock Trinity S2390 motherboard (used in Agilent logic analyzers) and I noticed all the 100uF 6.3V capacitors bulged and one burst:

Reminds me of Duralcell’s Alkaline batteries (never used) that leaked during storage (before the expiration date). Stop blaming the bad chemical formula on how users use them!

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Excellent Android Free and Open Source Apps

Simple Mobile Tools has very nice replacement for basic features no matter you are using the apps that came with your phone’s stock ROM or LineageOS which has the minimum. It’s lightweight yet it does a little more than most default basic apps

Phone

  • Yet Another Call Blocker (it downloads a database to your phone instead of uploading the phone number to the server to do the check)

Browser

  • Brave (Can use sync chain that your data is not stored in other people’s cloud)
  • DuckDuckGo

Maps & Navitation

  • OsmAnd – Offline Mobile Maps and Navigation
  • Organic Maps – very neat map apps that shows the walking trails!

I do not recommend Navit for Android as it’s very slow and broken. GTK+ style GUI looks very odd on Android.

Utilities

Productivity

Multimedia

  • Rumble
  • Odysee (LRBY)
  • Youtube Vanced (Youtube app broke which keeps demanding me to update when it’s already the latest)
    You can change the comments behavior in Vanced settings

Social Media

  • Twidere: excellent Twitter/Mastodon client (Twitter’s official client is very resource intensive and sluggish.)

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dd-wrt web admin UI WTF!? Inconspicuous invalid config combinations crashes your router out of the box.

I was puzzled by why my dd-wrt router behave erratically each time I change the “Start IP Address” in DHCP leases to an upper range and I just figured out why.

I hate the user interface of dd-wrt with a passion, but it’s the only open source firmware for one of my routers that signed Broadcom’s close source NDA to get its fucking driver SDK so I’m stuck with it:

Ugly as fuck

In the bad old days people think it’s a good idea to make 4 little edit boxes for IP addresses than checking if the input conforms to the IP address format with dots. But it cannot detect ‘.’ keypress and jump to the next box (use Tab instead). e.g.

Inconsistent state possible

Start IP address, which is dependent on Local IP Address, is not updated/reflected until you press “Save”. This means every time you make a change, you need to hit “Save” immediately so other dependent settings will make sense before you start editing them.

Features are arranged/grouped like config files

This is bare minimum effort on UI dev, which is not much better than going to linux prompt and edit the config files.

With config files, at least we’d be more careful and try to understand what each key-value pair mean and their relationship map. This lousy web admin UI interface gives a false impression that non-developers knows what they are doing, so it turns into a puzzle that we’ll have to google the answer for every fucking basic application.

Using the web UI instead of editing the config files feels like programming in assembly as an improvement over programming in raw machine code. It’s begrudgingly painful.

One example is the grouping for wireless radio. For most considerate web admin interface, the SSID are grouped logically with your WiFi password, but in dd-wrt, you set SSID in “Basic Settings” and the WiFi password under “Wirelesss Security”. Make sense for the programmer to decouple the radio from the access control (group by features), but it’s not application/use case oriented (group by radio interface), thus it frustrates users.

Non-intuitive (less common) presentation

As described above, out of developer’s convenience, dd-wrt’s web admin UI just do everything that makes beginners’ life miserable or just throw them off. e.g. Windows users are used to specifying the subnet mask in quad-dotted notation like 255.255.255.0, not the CIDR notation like /24:

Confusing names

The names are often too terse that creates confusion with similar named features in a lot of places.
e.g. “Wireless GUI Access” does not mean the welcome page for your Guest network, but whether the wireless client have access to the Router Administration‘s Web UI!

It’s probably a few minutes of extra thought to call it “Allow admin web UI: Yes/No”

Another example is AP Isolation, which is under Advanced settings tab for each radio:

Is this isolating APs in a mesh or isolating clients connected to the AP from each other? Turns out it’s the latter! Just say “(For this AP), allow connected wireless clients to talk to each other on the same network: Yes/No”. I think it’s a common use scenario that the regular users should be aware of and shouldn’t be stowed away with obscure radio/PHY-level tweaks (settings aimed for hackers).

Overloaded names

The admin web UI is littered with overloaded names/terms which means something completely different depending on context (like the settings 2 lines above). For example:

Image:Access point.jpg
Access Point (AP) mode
The SSID here is the SSID of the Access Point
(Wifi host. AP station accepting wirelesss clients)
Client/Repeater[Bridge] Mode
(all involves the dd-wrt router connecting to certain AP station/SSID)
The SSID here is the SSID where the Client/Repeater-Bridge/Client-Bridge is attempting to connect to that contains the uplink/WAN!

WTF?! The dialog box looks exactly the same despite the wifi section is acting like a completely different device! What the fuck is “Network Configuration: Unbridged” for a Client Bridge?! HELP!

Unchecked invalid combinations that crashes!

This is the most frustrating behavior and should be considered a bug. I wasted days resetting my router over and over and it keeps hanging randomly after I change the DHCP server’s starting IP address. This is the default out of the box settings:

Default DHCP settings. End IP Address is 192.168.1.253

End IP Address = Start IP Address + Maximum DHCP Users – 1. They probably chose this number to reserve 192.168.1.254 for static IP (like some admin page of other devices). 255 is broadcast IP so of course it shouldn’t be assigned

Moving the the “Start IP Address” up without adjusting “Maximum DHCP Users” accordingly will make your router behave erratically because the DHCP will try to lease IP out of range!

This will corrupt your router’s memory!

The End IP Address is displayed on Status -> LAN -> Dynamic Host Configuration Protocol -> DHCP Status. And here’s the WTF moment:

The End IP Address is now in a different subnet from the Start IP Address!
I’m using /24 so 192.168.1.X is different from 192.168.2.X.
From the web page, the attribute name is “dhcp_num”
This is the code that shows the derived ‘End IP Address” shown above

I don’t know how it is coded, but if this number is computed in a low level way, chances are it’ll write garbage to the memory (for example if the number is used as an array index). I think normally it’s checked in any not so shitty user interface so the invalid state/condition won’t propagate down the code and hang the router. But in my case it did. If I just reboot the router without resetting to the defaults, it’d just hang again after a few interactions (like moving between a few pages or applying a setting).

In any case, this check must be done at user level as even if the low level code say, quietly sets a valid default value when an invalid range was ‘entered’, it’d only surprise the user and make it even harder to troubleshoot. This UI bug is even less excusable as it’s more natural to have users enter the (Start, End) instead of (Start, # of slots). Probably takes half an hour more in coding to layout the UI code to enter ranges (add 4 boxes for quad-dotted notation for End IP and check them instead of just 1 box for # of DHCP leases), but making the user to do mental gymnastics and punish them by if they did it wrong is just outright terrible.

FreshTomato has quite a bit of learning curve, but at least it try to do something that’s sensible for users for common scenarios instead of sticking strictly to how the code/config files are written at developer’s level.

I seriously thought of tossing my router that only have dd-wrt as the only fully functional open source 3rd party firmware and find one that works with FreshTomato/OpenWRT/Merlin or the like. DD-WRT is powerful but the UI suck big time, not because the features overwhelm less tech savvy users, but it’s purely unnecessary torture and pain even you know why it’s done that way.

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Fedex loses your shipment, UPS roughen up your shipping boxes, and DHL (US) doesn’t care to ship.

There’s no good delivery service in the US. Each one of them just suck in a different way regardless of how much you pay them.

Fedex

Fedex lost my $1700 shipment (oscilloscope) in 2018 by scanning the package they mis-delivered* as delivered, and the people in Memphis didn’t give a damn about finding it. Unfortunately, the seller gave me free shipping and he didn’t insure the shipment nor require a signature; because the package was scanned as ‘delivered’, the ball is at my court.

Fedex basically told me to suck up the loss and take the $100 claim (that’s the default insurance).

Fedex’s fail opened a Pandora box of complex legal liability issues about who’s responsible (I believe it’s whoever that made the shipping insurance decisions is responsible).

The unit has an upside close to $10k if I get a chance to repair it, so it wasn’t just $1700 that was lost! That’s why I always get angry when Fedex lose my purchases (either breaking it or losing it) because the purchase price is the max of what I can claim so it can never cover the upside (which is often multiple times of what I’ve paid)!

Since this incident, I often prefer having eBay sellers ship on my account (or I make the label for them) because it’s easier for the recipient to do the claim (as shipping companies takes the one who pays them much more seriously). Also it’s kind to the seller because they’ve fulfilled their duty and it’s beyond their control if Fedex breaks it, they might need the money and don’t have the capacity to reimburse me first and wait for Fedex to reimburse them.

I used to love Fedex because Fedex Ground was more gentle handling packages. I’ve witnessed a few times inexperienced sellers screwed up on the packaging so bad that it couldn’t have possibly arrive in one piece unless the entire delivery chain was very gentle with the shipment and Fedex Ground saved the day and the instrument arrived without a dent.

This comment do not apply to Fedex Express as they broke my shipment a couple of times. They paid the claims but I wasn’t happy because the shipping damages costed more than my purchase price and I cannot find a comparable deal because those were rare finds.

I met a Fedex old-timer at the hub picking up a thrice missed deliver and shared my experience about how well Fedex saved the poorly packed shipments with extra care and UPS shipments often looked like the boxes was chewed by a dog. He loved his job and passionately told me that Ground and Express are like 2 separate entities and Fedex is self-insured: if Fedex break your package, they pay your claims out of their pocket, not through a 3rd party insurer (like UPS) so they feel the pain feedback more directly. I could at least feel that Fedex has people who cares.

I had been a loyal customer to Fedex even if they charged more than UPS. However, this incident change my mind and I switched to UPS (despite they are rough on packages) for good. Having a damaged shipment is better than no shipment. Since then I use Fedex only if my customer provides their Fedex account. If I am the one who makes the decision, I won’t use Fedex even if they are cheaper (which they are not).

I emailed their CEO and told them that they cannot just trust their drivers to scan the packages without GPS cross checking the address and take their word for it. By 2021, a few of their drivers still have a habit of scanning the package at the truck or anywhere that’s not at my door! Do they know much panic and agony they’ve created for the customer when the customer sees a ‘delivered’ email and look outside and see nothing!?

* I knew for 100% sure that it was misdelivered (not lost to porch pirates) because 3 weeks later, without Fedex’s involvement, an unrelated apartment leasing office 2 blocks down called me and said they had my package but no phone number (eBay stopped providing it to sellers) so they had to Google stalk me to find my contact info.

UPS

Despite my incoming UPS frequently arrive in beaten up boxes, they have yet to create big losses for me. Having thick and robust padding might mean your package might arrive in one piece, but it doesn’t stop whiplash from happening.

I shipped a PC-based oscilloscope to a customer 1 hr away from me and the PCI card got bumped out of the PCI socket on arrival. From my customer’s description, I knew right away it’s a PCI card that got displaced during shipping so I didn’t bother to have them ship it back to me, reseat it on my end, just to have UPS whiplash it again, so I drove to their site and reseat the card.

DHL

DHL entered US domestic market in 2003 and withdrew in 2009. They tried to be the discount delivery to undercut FedUPS in price by not having properly staffed locations and rely on everything filled online and sparsely located drop boxes.

What they didn’t realize is that like a buffet restaurant, logistics is an economies of scales game. You can easily get into a death spiral that people don’t come because you cut corners, and you are tempted to cut even more until you are eaten alive by fixed costs. With FedUPS already established their network, a new competitor cannot expect to scale up organically. People are not going to live with huge inconveniences to use your clumsy network just to save 5%~10% on shipping.

DHL still has a little presence in the US and their ‘sales’ (account manager) called the most persistently out of the 3 companies yet the rates they offer for small business is far more pricey than UPS and not even better than my Fedex account. Even for international shipping, which is supposed to be DHL’s stronghold, is more expensive than UPS after discounts.

That aside, even in the 2020s, they still work like in the 2000s which they don’t have dedicated shops and have a minimum crew and tiny vans picking up packages from drop-boxes and mom-and-pop shops. There’s absolutely no good reason to use them as they have no merits in any dimension whatsoever (speed, price, reliability, convenience). Why would I pay more to deal with more inconvenience?!

Today I got a foreign customer with a DHL account for me to ship against, and to my dismay, I found DHL is a total f*cking disgrace! It just felt like they’ve completely given up and waiting for the management to pull the plug! Here’s what I went through to ship a time-sensitive package:

  1. I haven’t logged in to make a shipping label for a while and noticed my email/login ID cannot get access to MyDHL+! I remember the last time I used DHL, it wasn’t called MyDHL+. That could be the reason.
  2. I can access my DHL billing account, which was separate from MyDHL. So I suspected they did not migrate my login information to MyDHL when they updated the system
  3. I emailed customer service and it took them a day to reply to my email EACH trip. The automatic reply reads “Thank you for contacting DHL Customer Billing Support Department. Our hours of operation are Monday-Friday, 8:00am-5:00pm (CST). We will return your request within 2 to 3 business days“. They are working at the French’s pace!
  4. Without logging in, I tried creating the e-waybill as a guest and they only take credit cards and there’s no option to use my customer’s shopping account, which means paying the retail rate at my expense! At least they should have the decency to have guests use recipient’s DHL account number and provide the credit card for charge-backs!
  5. This left going to the stores and fill in a waybill manually like a grandma as the only option to use my customer’s DHL account. I did it before in the past so I thought it’d work this time.
  6. I went to one of the crummy mailing shops taking packages for UPS and filled in the paper waybill there and was accepted.
  7. Since I’m at the mailing shop close to the cut-off time, I met the driver and he said manual/hand-written waybill is no longer accepted, but he’ll make the exception and take the loose paperwork to the office and make a label for me. This worried me as there’s no identifying information on the box so I’m gambling on the driver’s memory with no recourse or means to recover the package whatsoever if it wasn’t done correctly (i.e. broke chain of custody).
  8. 2 days later the package showed up at my door with DHL’s note in the pouch saying that the package was refused because they no longer accept manual waybill!
  9. WTF! It was an urgent package and they gave me force promises and wasted 2 days and it landed on a Saturday so I’d lose a whole weekend! WTF!?

This is an example of gross incompetence from IT to back-end to front-line workers. DHL in USA is broken, way broken, even for their international delivery services. DHL is now creating harms! I’d be saved had the workers told me to take my business elsewhere. I’d still had a an hour and a half to run to UPS if they had turned me down at the store!

DHL do not let you bill to an account unless you login
What I got from the package sent back to me, which wasted 2 days.
The driver said he’ll make the exception, but the office ended up rejecting it.
Not only it wasted 2 days, it landed me on a weekend so it could have been 3 days lost for an urgent package if it weren’t for UPS picking up on Saturdays!

Manual waybill wasn’t even one of the standard reasons for rejecting packages!
Sounds like DHL just whipped this cheapfuck policy out of their ass!

I ended up shipping with my own UPS account right away (using the expensive options to recover the lost time) and bill my customer later since the package is urgent and I don’t have time to go back and forth with this loser shipping company!

I’ve lost so much of my own time and energy fighting with this DHL nonsense, not to mention the stress as DHL was wasting days for an urgent shipment.

DHL has become so non-redeemable that unlike Fedex, I wouldn’t email their management to give them feedback because through this incident I can sense that nobody working there cares. The best I can do is to just tell my customers to stay away from DHL.

EDIT: The billing support just replied on Sunday after I replied to them with the DHL account number they asked for, what I got was “For further assistance on this shipment please contact our Customer Service at 1-800-225-5345 or MyDHL.Express.dhl Help and support Tip and Advise.“. I think they are not working in US hours despite their emails claimed so (likely Europe time), which would explain that they started the weekend earlier than I expected. More importantly, they are totally wasting my days by asking for details and in return gave me a generic boilerplate response that’s totally unhelpful. DHL in the US is hopeless.

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RS-232 Stop Bits in Agilent Instruments

Turns out Agilent instruments do not use the same defaults for the RS-232 in their instruments.

54600 series uses 1 stop bits (most common):

RS-232 modules used in old 54600 series
54620/54640 series (newer 54600 series)

However other bench instruments such as power supplies (E3640 series 663X series) and 33120A arbitrary waveform generator uses 2 stop bits (fixed regardless of parity), which is usually NOT THE DEFAULT for most terminal clients:

E3640 series and 33120A’s RS-232 configuration.
Parity only trade away one data bit, so it does not affect stop bit
663X series powers supplies’ programming manual aren’t explicit about that except in code example

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