Really the problem with the Dallas chips is ... they start using the battery as soon as they roll of the production line. Even when just lying on a shelf and never being used the battery will be used. So buying so called 'new old stock' is a risk. That being said what I usually do is use a small CNC to mill away part of the plastic (really it's an NVRAM chip with a seperate battery potted in a plastic cup), and replace the potted battery (remember to actually sever the connection or the internal battery will interfere) with a small cell battery holder. That way I can just put a new cell in whenever I need it. On the plus side you don't need to buy a 'new' dallas, you can use the depleted one for this just fine.

Excellent thank you

Enjoyed the ride-along. Great job 👍😁 You & HP need to be congratulated. Love the "classics". Darwin bless you for saving this one from the crap-heap and giving it new purpose. Would love to have this one on my bench. Cheers!

Calibration starts at 16:45. Here is a tip: if after you calibrate, your pp volts measurement is off, try correcting it by adjusting your probe compensation factor.

If your scope is failing several test that you did not expect it to, do not give up!!! Clean your BNCs with some electronics cleaner and try to use good probes. Ideally use high frequency new cable bnc to bnc to connect the back to the front inputs. Before doing the calibration I have been working on the PSU unit. It was blowing the mains fuses. I traced the problem to the input side full bridge rectifier . One diode was shorted. I saw bad electrolytic corrosion on the input side aluminium stud (a metal stick close to the input common mode inductor. The rest looked ok apart from some capacitors (I think capacitors around L4 and L6) held together with the inductors that are leaking badly. I swapped the bridge for the KBL4010 and powered it up. It works, I wonder what caused the bridge to fail. But capacitors need to be changed anyway. To whoever needs to fix their PSU here are some very useful links... enjoy: www.bitsavers.org/pdf/boschert/Boschert_OL25_Single-Stage_Power_Supply_Maintenance_Manual_May79.pdf And for those who cannot pay for the original schematics here is a reversed engineered schematic for a very similar PSU which however seems to have several component values that are different but is a good start: www.ukvac.com/forum/uploads/125/supplyHP54503.zip

Very good friend your video! I would need the motherboard wiring diagram do you have it?

I just got one of these. It doesn't work. Ran the self-check and ayy same exact results. So I know what I'm gonna go buy now!

It must have cost a fortune in 1989... I have a 54503A , outstanding scope for rf work up to vhf....

Sweeeeeeeet !

1989? Looks newer than that. Like early-mid 90s

It fails bnc connection on mine as well until scope warms up for about 10 minutes.

thank you ,I have the same model but with different error message .to clear, cycle power with one front-panel key pressed..., can you help please ?

Tell me if it is possible to replace the chip ds1235yw-120 with ds1230y-100 in the same oscillograph as Xp54501a. At first I bought ds1235i-120 but the problem is with the checksum. After reading the datasheet that differ only in performance and bought ds1230y-100. Now I'm worried that waiting and wasted money in vain.