JMP-1 Presets

[rtcook]

I have been working on a JMP-1 that I bought non-functioning. I have made progress with it. Tonight I fired it up and I now have power to everything (+15, -15, +5, 12V), but the HT.

While it was on I checked to see if the buttons worked and they all did. I was comparing the settings to what the manual says each should be and they do not match up. I did a factory reset and that did not help. The version on my chip is V2.01. That is the first version chip as my JMP-1 is an early 1992 Issue 1. The others I have seen have V2.02 chips. Could this be why my presets do not match up with the manual or do I have a bigger problem?

Thanks,

Roger

 

[rtcook]

Found my answer. The presets must be unlocked before you can do a factory reset. Once I unlocked them, the factory reset worked. All presets are like the manual now.

Now, I need to figure out the HT tap voltage issue.

 

[Jon Snell]

Check R86 10R fuseable resistor. ONLY fit a fuseable type or you may have a fire!
You are looking for about 160volts HT from the voltage multiplier.

 

[rtcook]

The 10R fusible resistors R85/R86 are on the 15-0-15 tap, not the HT tap.

Are you meaning 160V DC? That seems low.