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Born again Speccy user with problemsHello all, Firstly I'd like to say a big hello - this is my first post! When I was 8 or 9 or so my dad bought a ZX Spectrum 48K and a whole bunch o…
... that mean? Looking at the circuit diagrams I can see no ... it anyway. Looking at the circuit diagram once more, I realise ... />
I wouldn't bother replacing TR7 if it tests OK ... -
Please explain how a Kempston interface circuit works.Can someone help me understand how a Kempston joystick interface works, as I want to design and build my own as an experiment. I understand switches…
... to smooth out short term power dips caused by the chips ... that has a pulse detector circuit function.
[I][B ... -
IF1bis StabilityI just thought I would start a different thread relating to the IF1bis, and leave the copyrighters to it elsewhere...:-P I've had mine for a few mon…
... this lets you prototype a circuit to alleviate the problem). It ... 't have dedicated ground and power planes which is the usual ... decoupling capacitors sufficiently close to power pins? Are the decoupling capacitors ... -
IF1bis StabilityI just thought I would start a different thread relating to the IF1bis, and leave the copyrighters to it elsewhere...:-P I've had mine for a few mon…
... this lets you prototype a circuit to alleviate the problem). ... capacitors sufficiently close to power pins? Are the decoupling ... , operating system corruption at power-up is impossible(!!!), tested ... a machine having no internal power circuitry (supplied with +5V ... -
Faulty 128K toastrack keeps resettingHi. I have this toastrack which worked nicely for let's say 40 minutes and then a weird fault showed up. It keeps resetting over and over, sometimes…
... . You said the machine would power up and run fine for ... ;748776]You may check banking circuit that forces ROM bank (PAL ... -
ZX Spectrum + Please help!I wonder if anyone can help? I purchased a ZX Spectrum + from a Car Boot Sale last year, boxed, with games and leads. The problem is, it won't tune i…
... a fault with the internal power switching circuit (SMPSU). If the border ... -
48k Missing D15Got a 48k here that is missing D15 (just below right molex connector), someone removed it in the past, only just noticed it was gone after replacing …
... check, if this fails try replacing the coil
- Start removing ... resistance checks pass
- Apply power and test for good voltages ... above TR5 is the 3B power mod executed differently.
Grey +2 DiedHi all, Thrashing my +2 playing Mugsy last night and it did this... [URL="https://m.flickr.com/photos/83515822@N05/13012551693/lightbox/"]https://m…
... you know the voltage converter circuit is operating and producing 12 ... doubt your problem is a power supply one.Another "untested" dead spectrum...Hi, I'm looking for some suggestions on a faulty Spectrum I have picked up. I'll need to wait until tomorrow before posting pics, but the screen is …
... ICs or failure of their power supply or both.
circuit fails because of a bad capacitor. Check none of the power ... lines are shorted to 0V. Power on and check all 3 ...Another "untested" dead spectrum...Hi, I'm looking for some suggestions on a faulty Spectrum I have picked up. I'll need to wait until tomorrow before posting pics, but the screen is …
... this one was down to power problems
[IMG]http://hardware ... to that one. So hopefully replacing the above will work.Another "untested" dead spectrum...Hi, I'm looking for some suggestions on a faulty Spectrum I have picked up. I'll need to wait until tomorrow before posting pics, but the screen is …
... early-ish one).
Power up/down five or six ... okay, so does not need replacing. Keep your spare for another ...16K/48K Lower RAM (4116) replacement.You may want to read [URL="http://www.worldofspectrum.org/forums/showthread.php?t=37957"]this thread[/URL] for background information on the quest t…
... voltage converter circuit will be more lightly loaded. The power it has ...128+2 Help!Today the postie brought me an early Spectrum 128+2, it's a Z70700 Issue 1. Everything seems to be working ok, i.e it boots up and the keyboard work…
... the tape player circuit board has been changed to power the LED ... />
If anyone has a circuit diagram for the tape player ...Joystick Interfaces on +2AJust found out that my DK'Tronics joystick interface doesn't want to play with my +2A (black). The Kempston port works OK, but not the Sinclair port…
... effect with an auto-fire circuit varies depending on how it ... some appear to get some power through the fire button connection ...Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... /> ... If yes, have you tried replacing it?
... Do you now ... same colour every time you power up the Spectrum?
power up the Spectrum?
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... /> ... If yes, have you tried replacing it?
... Do you now ... same colour every time you power up the Spectrum?
power up the Spectrum?
power it up.
Thanks ...Weird output...Last week I found my old ZX Spectrum 48k and I tried to connect it to my tv... After tuning it (at 583MHz - C35, it's the only one with signal) it s…
... , the on-board switch mode power supply circuit (TR4, ZTX650 transistor) has ...Poorly Issue One 16k spectrum diagnosis?Hello, everyone. :smile: I was lucky enough to buy an Issue One 16k rubber key the other week; I didn't know it was an Issue One till I opened it up…
... spectacularly.
5. Notes: replacing the 4116 with Zorn's ... buzz. Have tried with two power supplies, both in spec. Have ...Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... modification to the on board power supply section to improve it ... same.
The modified circuit became standard on later issue ...is sega arcade stick compatible with 128+ toastrack?i bought 1 to use with my c64 but then learned i ran the risk of damaging my breadbin,so,i wondered if it was safely possible to use it on my +128 vi…
... , you risk shorting out the power when you press one of ... the interface and check the circuit. Look at what's connected ...Video on single transistor composite video modification for 48K SpectrumsI made a video on the single transistor composite video mod, using an Issue two Spectrum although it applies to all issues. Much better than the sing…
... with the 48K video circuit, the 128K circuit produces composite video ... function; that of short circuit protection. If the composite ... in the collector circuit. The entire video circuit +5V supply is ... mod uses this +5V power supply (the one originally ...Video on single transistor composite video modification for 48K SpectrumsI made a video on the single transistor composite video mod, using an Issue two Spectrum although it applies to all issues. Much better than the sing…
... composite signal and the +5V power supply for both the modulator ... the rest of the video circuit, turning the composite output into ...Trying to revive my +2B!Hey folks, Newly registered and looking for a fresh pair of eyes on my journey to restoring my +2B Spectrum :) I've done the Composite out conversi…
... ), or that it needs more power on the blanking pin see ... /+3 it involves a small circuit: [url]http://www.benophetinternet.nl ...Amplifier boxWould one of you have more information on this amplifier box (if it is one)? [IMG]http://schombi.de/onewebstatic/16faca329e-box_small.jpg[/IMG] Who …
... meant to plug the Speccy power supply into it, then plug ... the Speccy - so it leaches power from the Sinclair PSU. Not ... />
Looks like a printed circuit board, but a standard off ...Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... , the second test is to power down the Spectrum. Wait two ... by other components in the circuit, but should be no greater ...Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... a multiplexer, however the logic circuit it is part of controls ... />
With the switch "on", power up the Spectrum, and it ...Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... a multiplexer, however the logic circuit it is part of controls ... />
With the switch "on", power up the Spectrum, and it ...Plea for new hardwareI'm posting this as a poll as I want to judge if I'm a solo loon going on about this, or if people really are interested in either of the following S…
... off by the low voltage power supply which would complicate my ... power supply routing. With the MAX ... then pass it through this circuit [IMG]http://markamy.uwclub.net ... planning to add an alternate circuit for the 128k spectrums, which ...USB Keyboard Interface interest?Hi, I was wondering if anyone else out there is interested in a USB interface for the ZX Spectrum (particularly the rubber key models, though it sho…
... necessary depending on the output circuit in your individual microcontroller. You ... pull up resistors to back power it when the speccy is ...Poorly Issue One 16k spectrum diagnosis?Hello, everyone. :smile: I was lucky enough to buy an Issue One 16k rubber key the other week; I didn't know it was an Issue One till I opened it up…
... , which is what you report. Replacing resistors R17 - R23 with ones ... problem with one of their power supplies, though the symptoms are ...
