Pin 2 on connector CN1 is where the problem lies. When this pin is unsoldered the VCR fully funcitons, except no display. I ohmed that line and it reads +30Kohms, so why does this cause the switching PS to stop? I loaded this pin down with a 100mA bulb and the PS doesn't shut off, everything still functioned. I'm lost for an explanation here, without a schematic this is proving to be a pain in the ass-ets. David Lessard Alexandria Electronics Ontario-Canada mrfixit@xxxxxxxxxxx -----Original Message----- From: techassist-bounce@xxxxxxxxxxxxx [mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of J Silverman Sent: Friday, June 13, 2003 12:45 PM To: techassist@xxxxxxxxxxxxx Subject: [TechAssist] Re: JVC - VCR - HR-S4700U - P.S. Problems Just remembered that when I borrowed those JVC manuals I used to copy the power supply drawngs. CN1 goes to the display board. Pins 1 and 2 carry floating 7 volts for the filaments. Pin 3 carries -28 volts for the display driver IC (and maybe a memory or tuning chip). Pin 4 is ground. Pin 5 is the switched 5 volts. You may want to ohm the -28 volts to ground to see if the display driver IC is loading that line down. Jerry Silverman Greentron Inc 4 Newland Ave Greenville SC 29609 864 232 3889 Fax 271 2080 mailto:greentron@xxxxxxx ----- Original Message ----- From: "David Lessard" <mrfixit@xxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Thursday, June 12, 2003 9:21 PM Subject: [TechAssist] Re: JVC - VCR - HR-S4700U - P.S. Problems > Load, drum, capstan, all work. As I said in my previous post, this VCR > functions (but with no display) when connector CN1 is disconnected from > power supply board. What I need is information on this connector, where does > it go? It looks like over to RF modulator, but I'm not sure. What ever this > connector is feeding is the problem. Could someone with a schematic please > confirm this. Thanks in advance. > > David Lessard > Alexandria Electronics > Ontario-Canada > mrfixit@xxxxxxxxxxxx > > -----Original Message----- > From: techassist-bounce@xxxxxxxxxxxxx > [mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of becyn > Sent: Thursday, June 12, 2003 1:39 PM > To: techassist@xxxxxxxxxxxxx > Subject: [TechAssist] Re: JVC - VCR - HR-S4700U - P.S. Problems > > > I highly suspect that a motor drive IC has gone south. Check load, drum, > capstan, in that order. > > Jim McVey > McVey Alltronix > 327 Broadway > Newburgh Ny 12550 > ph: 845 561 8383 > fx: 845 561 9017 > Consumer electronics & > computer service. > Factory authorized for > over twenty brands. > > ----- Original Message ----- > From: "David Lessard" <mrfixit@xxxxxxxxxxx> > To: <techassist@xxxxxxxxxxxxx> > Sent: Thursday, June 12, 2003 1:53 PM > Subject: [TechAssist] Re: JVC - VCR - HR-S4700U - P.S. Problems > > > > No C33 in this SMPS. I changed C16 and C19, same results. You can hear the > > SMPS chirp a couple of times, then it shuts down. What I really need here > is > > reference to connector CN1 on the SMPS. Which circuitry does it feed? This > > is where the loading problem is. When CN1 is disconnected the VCR works > but > > without a display. Round two... > > > > David Lessard > > Alexanria Electronics > > Ontario-Canada > > mrfixit@xxxxxxxxxxx > > > > -----Original Message----- > > From: techassist-bounce@xxxxxxxxxxxxx > > [mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of J Silverman > > Sent: Thursday, June 12, 2003 11:30 AM > > To: techassist@xxxxxxxxxxxxx > > Subject: [TechAssist] Re: JVC - VCR - HR-S4700U - P.S. Problems > > > > > > Is there a C33 in the power supply on that model? > > Jerry Silverman > > Greentron Inc > > 4 Newland Ave > > Greenville SC 29609 > > 864 232 3889 > > Fax 271 2080 > > mailto:greentron@xxxxxxx > > ----- Original Message ----- > > From: "David Lessard" <mrfixit@xxxxxxxxxxx> > > To: <techassist@xxxxxxxxxxxxx> > > Sent: Wednesday, June 11, 2003 6:02 PM > > Subject: [TechAssist] JVC - VCR - HR-S4700U - P.S. Problems > > > > > > > VCR came in dead, found information referring to C16 & C19, they both > > > checked good and weren't replaced. I can get the VCR to come alive > (load, > > > play, ff, rr, etc.) but with no display when connector CN1 on the SMPS > > board > > > is disconnected. My question is, what circuit does CN1 supply? I didn't > > have > > > the time to check if the CABLE in via the RF modulator was working. The > > > above results were via RCA A/V jack to a monitor. A partial scan of the > > > circuit supplied by CN1 would be very helpful. Thanks techs. > > > > > > David Lessard > > > Alexandria Electronics > > > Ontario-Canada > > > mrfixit@xxxxxxxxxxx > > > > > > > > > **************************************************************************** > > * > > > The Tech Address Book: > > > http://www.tech-assist.org/secure/tip/contact.html > > > Add a Repair Tip Here, or Change/Remove your Email Address: > > > http://www.tech-assist.org/secure/tip/main.htm > > > Lost Password: > > > http://www.tech-assist.org and select "Lost your Login Info?". > > > Email Archives: > > > //www.freelists.org/archives/techassist/ > > > > > > > > **************************************************************************** > > * > > The Tech Address Book: > > http://www.tech-assist.org/secure/tip/contact.html > > Add a Repair Tip Here, or Change/Remove your Email Address: > > http://www.tech-assist.org/secure/tip/main.htm > > Lost Password: > > http://www.tech-assist.org and select "Lost your Login Info?". > > Email Archives: > > //www.freelists.org/archives/techassist/ > > > > > **************************************************************************** > * > > The Tech Address Book: > > http://www.tech-assist.org/secure/tip/contact.html > > Add a Repair Tip Here, or Change/Remove your Email Address: > > http://www.tech-assist.org/secure/tip/main.htm > > Lost Password: > > http://www.tech-assist.org and select "Lost your Login Info?". > > Email Archives: > > //www.freelists.org/archives/techassist/ > > > > > **************************************************************************** > * > The Tech Address Book: > http://www.tech-assist.org/secure/tip/contact.html > Add a Repair Tip Here, or Change/Remove your Email Address: > http://www.tech-assist.org/secure/tip/main.htm > Lost Password: > http://www.tech-assist.org and select "Lost your Login Info?". > Email Archives: > //www.freelists.org/archives/techassist/ > > **************************************************************************** * > The Tech Address Book: > http://www.tech-assist.org/secure/tip/contact.html > Add a Repair Tip Here, or Change/Remove your Email Address: > http://www.tech-assist.org/secure/tip/main.htm > Lost Password: > http://www.tech-assist.org and select "Lost your Login Info?". > Email Archives: > //www.freelists.org/archives/techassist/ > **************************************************************************** * The Tech Address Book: http://www.tech-assist.org/secure/tip/contact.html Add a Repair Tip Here, or Change/Remove your Email Address: http://www.tech-assist.org/secure/tip/main.htm Lost Password: http://www.tech-assist.org and select "Lost your Login Info?". 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