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Electronics => Repair => Topic started by: Westline on October 19, 2015, 05:36:59 am

Title: Uni-t utp3705s
Post by: Westline on October 19, 2015, 05:36:59 am

I Hope someone can give me some advice with this since I'm stuck.
I recently bought a uni t utp 3705s power supply seams like the same as a tenma 72-8700a.
2 channel 0-32v 0-5a.
During a anodizing job I messed up channel 1 it blew the fuse and since then is unregulated stuck at 32v.
Channel 2 is still fine.
I have swapped the power transistors and op amp between the 2 channels and no joy.

Can someone give me some advice on where I can start looking, it seems like a common problem on these units.

Kind regrads
Westline

Title: Re: Uni-t utp3705s
Post by: Westline on October 19, 2015, 05:03:33 pm

Hi I took another look and I forgot to mention the relays to switch to different coils on channel 1 clicks like crazy and sometimes the voltage jumps as high as 40v.
(http://images.tapatalk-cdn.com/15/10/19/576e840e2f8bb2ee43d08e4ef90c7655.jpg)(http://images.tapatalk-cdn.com/15/10/19/1d03500a703db05ce8ba163c2f635496.jpg)


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Title: Re: Uni-t utp3705s
Post by: Rasz on October 19, 2015, 06:49:35 pm

Quote from: Westline on October 19, 2015, 05:36:59 am

I recently bought

warranty

Title: Re: Uni-t utp3705s
Post by: Westline on October 19, 2015, 06:58:06 pm

One word... chineese


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