Re: SMPS low Vout
Once I get the projector going I might recap it... for troubleshooting purposes I guess it's fine at the moment.
By the way, here is Smokey the capacitor - https://www.badcaps.net/forum/showth...404#post880404
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Re: SMPS low Vout
Just for good measure I would recommend recapping this unit specifically the capacitor that are less than 100ufLeave a comment:
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Re: SMPS low Vout
Thanks for the reply... but it's my bad. I was measuring it wrong. In the SM there is no connector pinout and I assumed that it was rail-gnd rail-gnd... aligned, but it turned out that the ground are only 4 pins on one of the rows. Probably if I had paid more attention to the traces on the PSU board instead of focusing on the "usual suspects" would have saved me lot's of time
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Now, with the correct pinout, I'm able to read 2.63, 5.07 and 11.9V when the unit is "on". By the way, all caps are nichicon and all which I have measured are at least the uF shown on their labels... and that thing is 10+ years old. Well done nichicon
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Re: SMPS low Vout
could be the diode, BUT - is it running hot?
i'm thinking something may be overloading it.Leave a comment:
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SMPS low Vout
Hi there.
A quick one - BENQ projector SMPS, according to the SM there should be 2.5V, 5V and 12V at any time ( good ol' times, when there were no eco regulations ).
What I see though, is - +2.7V, +4.8V and -9.9V (I guess the polarity is irrelevant ).
So, the projector starts, and shows some functionality, but is not powering up the ballast ( there is power supply, but no command I guess ). Before troubleshooting more the MB ( there was a puffing smd capacitor for which I'll upload some media in the main cap thread ) and the ballast, I'd like to get the Vs within the specs. The 2.5 and 5V seem to be within the limits, but the 12V is low.
What I've done so far is to desolder the c707 and measure it... and it its fine - 707uF ESR 0.01.
What's next?Last edited by madan1; 02-09-2019, 05:00 AM.
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Hello,
I'm troubleshooting a PA speaker Mackie Th15 (schematics attached).
It is basically a smps with amp and some dsp.
The issue is that on the secondary side I read +/- ~23V instead of the expected +/- 38V. Indeed all secondary side and feedback/aux rails are like 1/2-3/5 of the expected values.
Q2, Q3, C35, C40, C33, C36, C41 and C42 were tested out of circuit with a component tester and read fine. Most of the other components on the primary were tested in circuit and seem to be fine. +HV to -HV on primary is ~330V.
By the way, the ferrite core of L10 is broken,... -
One of my friends brought to me this Projector after he missed up with the ballast. its Digital UART serial Bus function.
He told:
he was trying to trace the serial bus code with USB Logic on 2CH TX & RX. he used to soldering the CH wire to PIN 1 of 2 optocoupler PC123, and as soon he switched the projector ON, he heard once at time crack noise. result his logic went dead & the projector shutdown and give blinking led error.. and always his projector wont start any more register same error all 3 LED power lamp Temo blinking Red.
Trouble shooting :
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This specification for the Lenovo ThinkPad P51s + ThinkPad Stack Mobile Projector Mobile workstation can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the P51s + ThinkPad Stack Mobile Projector boardview and P51s + ThinkPad Stack Mobile Projector schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum....09-06-2024, 06:11 AM
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This relic from a technology path that came to a dead end (but still has historical interest) was brought in with a dead SMPS, which is based around a MK1210 device. I got it going after a battle. It seems to have a strange design - if it's not getting feedback that the secondary is OK it cause the big FET to go into full conduction and overloads resulting in a blown fuse at best or something worse! I'm using a Dim Bulb Tester (70W/230V) which thankfully has saved the day a number of times whilst repairing.
Now, it loads a CD OK. The motor voltage output (which is built onto the SMPS... -
Hi all, I just need to know that, can i use SMPS type power supply to test and short circuit detection on a laptop motherboard?
I saw 95% of repair guys are using only Linear bench power supply. linear bench power supply is pricy, thats why i planned to get one SMPS supply.
i know that in linear power supply the noise will be very low comparing to SMPS supply....
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