Need of a manul.
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Hello
Got this speaker from a friend , defective. Power led comes on and off , in a loop.
Disassembled, got the board out, and after a bit of measuring I found a low resistance on a 5v6 line. With a bit of current I found a transistor heating up on that line (labeled T1 and 113 as on pic).
After removing this guy, I got a value of 0.7 in diode mode on that 5v6 line, which before had 0.02 or something like that.
I tested powering it up without the IC, and the speaker turns on and stays on, and works fine
Still, I need to replace this transistor.... -
Hi folks!
I have some kind of memory problem on Lenovo laptop. I was initially able to install windows after several tries since the laptop did freeze in middle of those attempts.
Eventually I discovered that it was related to moving the laptop.
Later on it even stopped booting unless I pressed around the memory slot. (no keyboard LEDs only power button responds)
If I remove the RAM I get the beeps that RAM is missing. Inserting the RAM there is silence and it will not boot most of the time. No picture.
I removed the board got one of those memory slot testers... -
Hi friends
I have reverse engineered this tester, schematic is attached and is complete except for capacitor values. These testers annoyingly have no model number but they are the ones you find on the first page of just about any website if you type in "18650 4-channel tester". There is also a 2-channel variant and a newer 8-channel variant. They are very cheap (about £15) and can measure voltage, current, internal resistance and capacity. They have a multicolour display for all these statistics. They also have terminal blocks so that if you want to use a breakout board... -
https://www.ebay.com/itm/405035016711
I got this device yesterday and did some testing on some tabbing and some incandescent light bulbs and it seems to work very well from what I can tell but how do I know how accurate the m-ohms section is what can I use to verify it accurately I also tested some li-ion battery cells and this seems to be fairly accurate because I have another tester and they seem to agree with each other
I also checked some capacitors with it that were brand new and seem to show about what I expected to see with my blue capacitor tester so I think it... -
hi people, i need some help to identify a transistor(q14) that is missing on the board, so the gpu has no voltage i think that q14 activate the phases for gpu, but i dont have schematic or boardview, but i think its the same transistor than q15 and q16, thanks...