I have a generic DVOM that is having issues. It wont read volts or Ohms, but it will read zero Ohms when shorting the leads. The shunt inside looks to be burnt. Can I use solid copper wire to replace it?
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Re: Repairing shunt in DVOM??
1) Can we get a picture of the front of it so we can see the brand name and model number?
2) To measure volts and ohms, the current shunt is not used at all. Do not replace the shunt with a copper wire.
3) In cheaper multimeters, the current shunt usually looks like crap. From the picture, it looks normal to me.
4) If you try to measure an AA battery, what DC volts is the multimeter showing?--- begin sig file ---
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Re: Repairing shunt in DVOM??
5) A clear focused picture of the entire backside pcb would also help.--- begin sig file ---
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Re: Repairing shunt in DVOM??
Your pictures are blurry. If you're talking about the solder, it was added to decrease the shunt's resistance. Sometimes it is nicked or crimped to increase the resistance. This is done to improve the accuracy of the high-current range.
Absolutely, positively, what he said.Comment
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Re: Repairing shunt in DVOM??
6) Did you have an oops moment? Like trying to measure mains AC with the dial set on resistance?--- begin sig file ---
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We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.
Please do not post inline and offsite as they slow down the loading of pages.
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Laptop is HP Envy x360 13-bf0013dx, hp website link, it's an i7-1250U with 8 gig onboard ram.
Platform: ipa32 la-m024p rev 1b
Originally you'd plug power supply into it and it would take up to 1.2 amps and then drop to 200 milliamps and then go back up again to 1.2, staying all the while at 5 volts. Pressing power button would results in power LED blinking amber 3 times. 3.3 volt rail, 5.1 volt rail present, main power rail 8.8 volts. Power button test pads near EC chip 2.7 volts.
I found a short on the other side:
...10-04-2025, 05:03 PM -
Hi everyone,
Brought a non functionnal PS5. Apparently only a bad PSU...
No beep, nothing.
After some tests i found this :
- PSU is fine (12 volts stable)
- 12 volts line is shorted
- DA9065 was fried, F7003 also => Replaced both of them, short is gone on 12 volts line, no dead short anywhere else.
- By the way, nothing change. No signal, no power, no beep.
Mesuring all rails with my workbench psu (12 volts input)
- 0.00 amp drawing
- 12 volts, 5 volts, 2 volts, 1,15 volts are presents (suppose new DA9065 do is... -
hi all,
first of all: i'm a (motivated) newbie, so please forgive me any stupid question i may or may not ask
i'm currently repairing a projector: Epson EB-U42 that doesn't start (no lights, nothing).
what i've found so far:
- the PSU does its job and supplies 12V to the mainboard via the connector.
- shortly thereafter, there is a mosfet (TS420-600B) where i can test 12V on the one side (in the data sheet this side is called Anode), Gate 0V, Kathode shorted to ground
- not far away, there's the first cap with a resistance of 0.7 ohms.... -
Hi everyone, I replaced this motherboard because it was important to get it working, but it's been with me for a very long time. Now I finally have time to figure out what the problem is,
I've never encountered something like this before;
No charging light, full dead
Lenovo Ideapad 330-17ICH- PL3102: 5 ohms
- PL3001: 3.2 ohms
- PL3101: 2 ohms
- PL5801: 3.5 ohms
- PL5501: 270 ohms
- PL701: 35 ohms
- PL501: 146 ohms
- PL503: 390 ohms
- PL402: OL (0.27V) +5VALW_P
- PL301: OL
- PL401: OL (0.03V) +3VALW_P
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Hi everyone.
I am diagnosing my personal laptop, because it wont power on and no leds light up.
At the dc-in there are 8 pins, 1 and 2 shows healthy 19.66 volts. The next three are ground, but the 6th one shows .283 volts. This is strange to me, it should be 3.3 or 5 or aome volts not 0.283v. As I am new to this, I would like some guidance. Please someone advise me on what to check next.
Oh the boardview and schematics I am using is for a similar model as I cannot find the proper one anywhere. Quanta DA0P5HMB8F1 rev F. Nowhere on the internet.09-23-2025, 12:13 PM
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