----- Original Message -----From: Gary BrummSent: Tuesday, September 22, 2009 9:44 PMSubject: RE: [Ensoniq-VFX-SD] Re: newbie
Hi Jamie,
I do not remember a -35 from the PS .I will check. Sometime the display lights up all segments and sometimes it is blank .the buttons
are non-responsive for the most part seems different every time I start it up. It also came with a Cesium Sound ROM Cart.
Thanks,
Gary
From: Ensoniq-VFX-SD@yahoogroups.com [mailto:Ensoniq-VFX-SD@yahoogroups.com] On Behalf Of jammie
Sent: Tuesday, September 22, 2009 10:12 AM
To: Ensoniq-VFX-SD@yahoogroups.com
Subject: Re: [Ensoniq-VFX-SD] Re: newbie
its +5v and -5v for the filament of the fip then theres a -35v from psu for the anode and cathode suplly
via 2 display drivers 1 does the row 1 does the colume the 1 display driver also does the push button switches and drives the leds for those swithches via led drivers and logic
its the same design used in the eps /eps16+/asr10/vfx-sd/and the ts10/12 until they did the purple lcd screen for the asr88 and later asr10
----- Original Message -----
From: tomlinson6050
Sent: Tuesday, September 22, 2009 5:46 PM
Subject: [Ensoniq-VFX-SD] Re: newbie
i'm in Richmond KY. about 100 mi south of Cincinatti.
my thoughts on your VFX:
i don't think there is a -5 volt line: two +5s
there should be a 50-volt output from the power supply for the vacuum display.
when you open the front panel, there will be three connectors to the panel /display board: one on the left, two on the right. check them for corrosion.
thanks for the welcome
bill
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Message
Re: [Ensoniq-VFX-SD] Re: newbie
2009-09-23 by jammie
it sounds to me that you are loosing the power to
the upd 7538 this gets its power from the +5x votltage regulator from the psu
this ic does the push buttons
the pin 23 and 42 of the fip has 5.5 ac voltage the
-35 volts goes to the pin 4 its the refrence voltage for the anode
row cathode column comes from ic 58341
check j1 this is the power to the display board
check for oxidisation deoxit
j2 is the sliders and the clock and digital
instructions for the 7538
i have the schematics infront of me i would check
the psu as that seems the culprite to me check q5 its a 7805 voltage
regulator check the 3 caps 4700uf 16v you should have a refrence 17vdc at
the input to the regulator
the q5 regulator is the supply for the display
board ic and the floppy if you have 1 on your model