Looking over their web page FAQ they claim to do around 50 different phosphors.I also sent them a note from there contact listing. I'm thinking at this point that cost will be the big factor.

... What about R776 or its connection to R775 being open..? I know you checked everything but the mystery remains... It can't be a shorted R777, because you said that adjusting R775 does nothing. A

- 7 V is just about the voltage at the base of Q772 (and the slider of R775) under normal circumstances... Raymond

Interesting. I am going to contact them. If they can redo the phosphore maybe they could change it to a different one. Depending on cost of course. Thanks.

Just curious. I found a company that STILL does CRT rebuilding, wondering if anyone on the list has tried them or looked into it. https://www.thomaselectronics.com/repair-overhaul/ Not sure if all

Unfortunately, it does not appear that there is any way to adjust the brightness.  They built the main power supply and CCFL inverter all on one board.  There is nothing to adjust.  The service

Addition: Strictly speaking, you *are* correct, of course. It's just that the - 30 V *does* exist without the regulation part being functional - or present. In fact, the voltage would probably try to

I think that's incorrect: Whenever - 40 V is present, Q788 is pulled into conduction by R787 (to gnd), causing the output voltage to move from 0 V towards - 30 V. The regulating circuit *reduces* that

Dennis: The parts in faded print are R773 and C773. They are not on the circuit board. The circuit design is not well described in the service manual. No normal voltages and currents are mentioned

Good news Victor, congratulations! I think my 454 has no net filter at all, could a filter be present in later S/N? Albert

You can do that, possibly.  It depends on whether or not the display has an easily replaceable CCFL bulb. What you'd need would be an LED strip, the appropriate resistors and LEDs.  You'd need a

Usually these CFL inverters used for the backlight (at least in laptops) have an analog pin to adjust the brightness of the CFL, also there should be some room to play with using the contrast setting

Yes, that is what I got.  They do work in the TDS2000 but I think the backlight is a bit too bright.  There doesn't seem to be any way to change it short of getting rid of the CFL bulb and putting

My service manual (070-1414-00) shows the main power supply on schematics sheet 11. R773 and C773 are shaded. I made the assumption that Gary is talking about the + and - 30 V supplies, as they are

Using Google I found this: https://www.goldmine-elec-products.com/prodinfo.asp?number=G19815

I read the manual a little closer.  The brightness command only works on the TPS2000, not TDS2000.  I guess I am out of luck. Tom

Hi Gary, Which parts on which schematics are shown in shaded text? Dennis Tillman W7pF TekScopes Moderator

Hi Gary, I assume that you're talking about the main power supply's + and - 30 V supplies. You may not like the circuits but a few things about your unit I consider a given: - It has worked at some

This power supply does not start up correctly. The output is set at 7 Volts both plus and minus. The variable adjustment controls have no effect. The schematic shows several components in shaded

Albert, Yesterday I receive from our well known friends in Greece the HV capacitor (C1460 - 500pF 20kV) suppose to be faulty. Today I install it and my 454 in now alive after 25 years sited on a shelf