sorenb

de-attach the high voltage from the board. put the LV+ to the HV+ ...put the LV- to a DMM common, and put the probe from the DMM at the tail ...if you get steady current it probably works

Well, Sherlock, is it working? if not, you did some thingS wrong

Not what I am asking. If you use the SPLIT PSU boards, and have two identical HV boards ....and wire GND to Ground, you'll have +457 on both PSU's ... Same goes for the GRLV split boards So, try to be more specific and give more information if you want help ... there are lots of skilled people here that might give you help or a hint to what is wrong, but they need a bit more than: "it not work, what is wrong?"

... in context of your questions/information so far, I dare to ask, do you by any chance wired the Split PSU so you really have 457 and 14.96 on both positive and the terminal supposed to be negative?

Check that you have - used the right transistors/ resistor values - have the right voltages from the PSU at the PSU connector - wired everything correctly. and check the voltages at the amp board as well - no shorts and/or blobs...if you have used too much solder it might hide a bad joint ...clean up with some wick and re-do with extra flux If the above doesn't make things work, post a close up picture of your board top and bottom.

everything but output boards are mounted on bottom plate

Finally received Front/Back plate for the 5U Dissipante - almost took forever. Decided to have a groove dividing the front plate into an upper 2U and a lower 3U, to have it look less bulky; it's still one 5U piece. The "pi" sort of symbols the topology To be continued ...

....if one doesn't want the buffer/servo you just jumper it ...

Baseboard seems to come in an edition including buffer and servo ...might be worth postponing that part of the group buy

You can trim the CSS's using only LV and a DMM in mA mode (assuming AMP board is not connected to anything): Connect LV+ -> AMP HV+ Connect LV- -> DMM (Common) Connect DMM.(+) -> the probe put the probe to the tail of the CSS (the Drain of the Sics (middle leg)) Now you'll have the CSS current reading directly on the meter, and the CSS can be trimmed to what ever current < 27mA you have sinks for (one might shoot a mA lower as the current grows a bit at higher voltage and heat). Trimming the output stage tail resistor to get the amp in balance and DC balance requires all voltages

You need all the voltages to work before doing any further trouble shooting

I guess you mean totals row? should be ok now

more like a psychiatrist and pharmacist it seems

all is in transit by now. Please let me know when stuff arrives.

Caps arrived - shipping tomorrow friday Please keep yourself updated in rgrds to shipping costs here As usual, I'll use cheapest shipping option available; if someone wants tracking/insurance they need to explicit ask for it.

might be stretching it a bit ... the two 1Meg + trim is really only needed if you care about mV accuracy ...you can omit those

15V

Caps has been shipped from the Über country ... I expect them to land first thing next week ... thanks for your patience

I guess gwrskien has a point as some fab houses do charge extra going for more oz ... however, in rgrds to PCBNet it doesn't really make much difference. For re-work abuse 2oz is usually fine - 1oz typically cannot handle much abuse . @nopants in comparison to how much green we are speding on components, chassis and so forth, I agree ...doesn't really matter much

any chance for some quotes in the sheet?

no room for it ... if you want a better CCS you might do a T2-Style on a separat board

as far as I remember I use 12V+5V back2back 1W's ...probably not critical 22awg is probably plenty For testing you can: Power up: bring up the drivers - wait until output settles - bring up the output stage Power down: bring down the output stage - wait until the HV900 < 200V - power off the drivers That works for me. Keeping the HV900 < 200V you can investigate the troubling behavior, having meters on the current limiter resistors of output stage and HV900s As far as I understand from Kevin he hasn't had problems in the lab, but he used some film on ceramic resistors at 10W's for current limiter. The DigiKey you found is 100W/700V rated and will most likely not break down.

I would assume that having some more robust 120ohm's will easen things quite a bit, as it will take a considerably amount of time before a pair of those break down, and at that time the current limiter from the HV900 should have kicked in and the situation being under control until the driver output has settled

two of those in series to get to 1kV for the 120ohms ...well only 100ohms are available ...so four it is