Damaged Volts/Div settings on PCS500

I have a PCS500 and a PCG10/8016(kit). Have not used them for years but recently had a project that required them. I inadvertently crossed the power supplies and supplied the PCS500 with 12vdc. The PCG10/8016 did not function on the 9vdc and I realized the problem when I touch the PCS500 case and it was hot. I immediately pulled all plugs and traced the problem. Current status is the PCG10/8016 is undamaged. The PCS500 works as follows. The Software version 4.05 calibrates OK and generates a Calibration.log that is within design specs. Channel 2 functions normally with no issues. Channel 1 functions normally except for Volts/Div. 15V and 5V where the trace position drops off the screen when activated. This also prevents the AUTOSET, channel 1 from working. What components on the smd board only affect 15V and 5V Channel 1 settings? I have found no schematics for the PCS500 but I do have the tools for SMD work.

On 15V and 5V settings the relay RY4 should be activated (ON).
The circuit diagram and other documents are on the installation CD.
You can also download them here: box.net/shared/ybz9k9adq4

Ran an on board test of RY4 and though it receives power, it does not close. While powered on the 5V setting , I jumpered the relay and the trace returned on the screen. Same with the 15V setting. RY4 (SIR-S4-105A) is definitely bad. On searching the WEB, the SIR-S4-105A does not appear to be readily available any more. I did find a Hamlin HE3621 A 0510 that almost matches. The size and footprint match. The specs are the same or better with 2 exceptions. Drop-out voltage is 0.5 VDC instead of 0.8 VDC and the Max coil voltage is 14 VDC instead of 16 VDC. Jameco part # 1860088. I see no reason this will not work. Thankyou very much for the help VEL255. I will order a new regulator as well as I am sure I shortened its life substantially. Thanks again, Steve.

The replacement relay you selected seems to be a good choice.

Normally the PCS500 works well with 12V supply too.
The regulator is slightly warmer though…

I agree, If I recall I think it can take up to 32 volts with proper heat sink. It was not on very long. The relay failure was probably unrelated. I ordered 5 relays from Mouser along with the higher quality capacitors for my Chesster Phantom computer recapping project, the reason I pulled out my oscilloscope in the first place. Thanks again for the help. Steve

No problem at all.
Indeed, most probably the failure was just a coincidence but not related.