Category Archives: Electronics

Samsung Galaxy Note 3 Charge and USB-OTG simultaneously

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I’d like to charge my phone and use USB devices at the same time, but it seems like it requires a 64.9kOhm resistor from sensor ID pin (micro USB) to ground. Instead of melting a USB-OTG cable, I bought this adapter (schematics here)

micro USB3.0 Type B Male to USB3.0 Type A Female adapter

so that I can have direct access to the ID pin. This is a USB 3.0 give that I have a Galaxy Note 3. The same principles apply to the USB 2.0 versions for Galaxy Note 4.

According to this website, fsa9480_i2c.h has the table for the resistor ID values. Turns out 64.9kOhm is the one for both charging (slowly) and using USB devices (like mouse, network adapter, etc.).

RID_USB_OTG_MODE,	/* 0 0 0 0 0 	GND

USB OTG Mode

              */
RID_AUD_SEND_END_BTN,	/* 0 0 0 0 1 	2K		Audio Send_End Button*/
RID_AUD_REMOTE_S1_BTN,	/* 0 0 0 1 0 	2.604K		Audio Remote S1 Button */
RID_AUD_REMOTE_S2_BTN,	/* 0 0 0 1 1 	3.208K		Audio Remote S2 Button                         */
RID_AUD_REMOTE_S3_BTN,	/* 0 0 1 0 0 	4.014K		Audio Remote S3 Button */
RID_AUD_REMOTE_S4_BTN,	/* 0 0 1 0 1 	4.82K		Audio Remote S4 Button */
RID_AUD_REMOTE_S5_BTN,	/* 0 0 1 1 0 	6.03K		Audio Remote S5 Button */
RID_AUD_REMOTE_S6_BTN,	/* 0 0 1 1 1 	8.03K		Audio Remote S6 Button */
RID_AUD_REMOTE_S7_BTN,	/* 0 1 0 0 0 	10.03K		Audio Remote S7 Button */
RID_AUD_REMOTE_S8_BTN,	/* 0 1 0 0 1 	12.03K		Audio Remote S8 Button */
RID_AUD_REMOTE_S9_BTN,	/* 0 1 0 1 0 	14.46K		Audio Remote S9 Button */
RID_AUD_REMOTE_S10_BTN,	/* 0 1 0 1 1 	17.26K		Audio Remote S10 Button */
RID_AUD_REMOTE_S11_BTN,	/* 0 1 1 0 0 	20.5K		Audio Remote S11 Button */
RID_AUD_REMOTE_S12_BTN,	/* 0 1 1 0 1 	24.07K		Audio Remote S12 Button */
RID_RESERVED_1,		/* 0 1 1 1 0 	28.7K		Reserved Accessory #1 */
RID_RESERVED_2,		/* 0 1 1 1 1 	34K 		Reserved Accessory #2 */
RID_RESERVED_3,		/* 1 0 0 0 0 	40.2K		Reserved Accessory #3 */
RID_RESERVED_4,		/* 1 0 0 0 1 	49.9K		Reserved Accessory #4 */
RID_RESERVED_5,		/* 1 0 0 1 0 	64.9K		Reserved Accessory #5 */
RID_AUD_DEV_TY_2,	/* 1 0 0 1 1 	80.07K		Audio Device Type 2 */
RID_PHONE_PWD_DEV,	/* 1 0 1 0 0 	102K		Phone Powered Device */
RID_TTY_CONVERTER,	/* 1 0 1 0 1 	121K		TTY Converter */
RID_UART_CABLE,		/* 1 0 1 1 0 	150K		UART Cable */
RID_CEA936A_TY_1,	/* 1 0 1 1 1 	200K		CEA936A Type-1 Charger(1) */
RID_FM_BOOT_OFF_USB,	/* 1 1 0 0 0 	255K		Factory Mode Boot OFF-USB */
RID_FM_BOOT_ON_USB,	/* 1 1 0 0 1 	301K		Factory Mode Boot ON-USB */
RID_AUD_VDO_CABLE,	/* 1 1 0 1 0 	365K		Audio/Video Cable */
RID_CEA936A_TY_2,	/* 1 1 0 1 1 	442K		CEA936A Type-2 Charger(1) */
RID_FM_BOOT_OFF_UART,	/* 1 1 1 0 0 	523K		Factory Mode Boot OFF-UART */
RID_FM_BOOT_ON_UART,	/* 1 1 1 0 1 	619K		Factory Mode Boot ON-UART */
RID_AUD_DEV_TY_1_REMOTE,	/* 1 1 1 1 0 	1000.07K	Audio Device Type 1 with Remote(1) */
RID_AUD_DEV_TY_1_SEND = RID_AUD_DEV_TY_1_REMOTE ,		/* 1 1 1 1 0 	1002K		Audio Device Type 1 / Only Send-End(2) */
RID_USB_MODE,		/* 1 1 1 1 1 	Open		USB Mode, Dedicated Charger or Accessory Detach */

 

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Data Precision 8200 Repair Service

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I just bought a big lot of Data Precision 8200 and some Analogic AN3200 DC Voltage/Current Calibrators with a bunch of hard to find (unobtainium) genuine parts (relays, switches, hardware, regulator and amp ICs, whole modules, transformers) that that I believe it’s the leftovers of a closed down repair shop.

That means I’ll have all the materials needed to service and upgrade Analogic / Data Precision 8200 that you are unlikely to be able to find elsewhere.

Data Precision 8200 is the official unit to field adjust TDS 500~800 series oscilloscopes as the automation software (GPIB) was hard-coded to this model. Nonetheless, I find it a reliable reference for verifying oscilloscope performance and adjusting my multimeters as well.

Call me at 949-682-8145 for a repair quote or if you are interested in buying a unit. GPIB and 1kV option can be ordered for extra, either with the unit or service upgrade.

 

 

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Duracell leaks in original package before being used!

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I knew Duracell is known for leaking when left in equipment for too long (too numerous to count: I had it leaked in wireless mouse, remote control, clocks, etc), but I always thought it’s my fault for leaving them in my electronics for a long time.

Today I got my answer: it’s not my fault that the batteries leaked. I just opened a new box of 4 AAA Duracells, and one of the new unused battery (the marking says it expires in 2023. It’s 2019 at the time of writing). I bought them from Tigerdirect so it’s likely to be genuine (on 10/2015). Here’s the pictures:

Not only I am not going to get Duracell batteries even if they are free, I’m going to toss all Duracell I have. It’s nothing but a menace. It’s worse than white label brands as it’s known to leak. It has to be a design or chemical formula or manufacturing process problem they have. By no means it’s an isolated incident.

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Aging problem just from storage Working 6632B stored for 10 years has a failed tantalum cap

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I fired up one of my 6632B stored for almost 10 years and smelled burned electronics, despite everything is functioning. I tested the unit immediately when I bought them a decade ago and it was working fine, so it’s an example where electronics can deteriorate by storing (even in temperature controlled, dry environment).

Since I see smoke, I turned everything off immediately and investigated. Turns out one of the tantalum capacitors in the processor/controller board gave in:

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Wobbling rotary encoder in Agilent/HP/Keysight 6630B series 6631B, 6632B, 6633B, 6634B, 6634A, 6635A, 66332A*

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6630 series system power supply is sturdy as a rock, but has a rotary encoder sticking out that it’s almost guaranteed to wobble if you buy it used.

I thought they would have known better to secure the rotary encoder with a nut so it won’t wobble (HP usually does a perfect job making their designs reliable. This one is a rare miss), so I opened it up to see what I can do about it.

My initial guess was that the solder joints were weakened as it was used to mechanically support external forces for users of the dial. But I was wrong. Here’s what I’ve found:

The weak metal strip retainers gave in and the whole rotary encoder is about to break loose! The encoder was actually still functioning before I opened the case up. So HP assumed their vendor for the mechanical rotary encoder did a good job withstanding frequent wiggling. Apparently their vendor completely failed them: the metal retainer design was hopelessly flimsy that I wouldn’t even consider using it even in light-usage applications! FAIL!

There’s a huge number of these high quality power supplies on the market because Motorola/Nokia closed down their massive operations, flooding the market with 6632Bs for years to come.

I’ll now strengthen (I came up with a solid technique to make sure the dial will never fall apart again) the 6632Bs I have for sale to businesses that needs a perfect unit (which I sell for $699/ea). If you are a hobbyist, feel free to send me a message and I’ll tell you how to do it, provided that you do not share it with anybody else (I’ll trust you). If you are a business, I can restore 6630B series to a professionally salable state starting at $499.

* Note that I included 66332A despite it’s a mobile communication DC source (66300 series) here because the guts of it is actually 6630 series. Every other 66300 series (3 Amps max) or less has a different form factor (that’s more like a 33120A) and the only odd one out of the series is 6632A (5 Amps max).

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