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Old 5th Jun 2019, 9:03 pm   #69
WaveyDipole
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Join Date: Mar 2013
Location: Leicester, UK
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Default Re: Hameg HM307-3 Cleaning and Repair

Quote:
Originally Posted by OldTechFan96 View Post
Does anybody wonder if something connected to the -1000V rail is pulling it down?

I'm going to lift one end of R305 and see what I measure.
Is this with the CRT circuit connected or not? As far as I can tell, Z212/R237 on the CRT circuit is the only point that the -1kv line connects with. I initially suggested that you disconnect at this point so as to determine whether the CRT circuit was unduly loading the PSU down, but after doing so you reported that the output from the PSU was still low, which pointed to a problem with the PSU itself. Now that you have replaced the IC and the transistor, it might be worth re-connecting it to give the PSU a load to regulate and measure again. If it is still low either way, then something else must be going on.

What voltages do you measure across the following individual resistors: R310, R312 and R313?
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