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Spectrum Plus display issueHi, does anyone know if this is fixable at all by someone with no experience? From looking on a similar post on World of Spectrum forum they mention…
... both the voltage conversion circuitry and at least one lower RAM chip ... further guess is that the RAM failure is interfering with the ... -
New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... can be caused by lower RAM failure, or by a CPU ... />
However the low -5v voltage makes me suspicious. I would ... the Issue 2!), then rechecking voltage and going from there.
Simple Question! RAM InterfaceI was messing around on my spectrum yesterday and blew it up! Im sure it has to do with the RAM joystick interface I bought but hadn't tested. Is the…
... TR4 in the Spectrum's voltage converter circuit has failed. It ... or more of the lower RAM ICs to fail. It should ... until any fault in the voltage converter circuit has been corrected ...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…
... one or more faulty 4116 RAM ICs. Do not power on ... few seconds to notice the voltage convertor circuit is overloaded before ...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…
... one or more faulty 4116 RAM ICs. Do not power on ... few seconds to notice the voltage convertor circuit is overloaded before ... -x-1-bit-NMOS-Dynamic-RAM-DRAM-Vintage-Siemens-4116-IC ...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…
... more Zorn sells replacement lower RAM boards which replace all 8 ... 5 volts, so if the voltage conversion circuitry ever goes south ...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…
... more Zorn sells replacement lower RAM boards which replace all 8 ... 5 volts, so if the voltage conversion circuitry ever goes south ...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…
4.3v is very low for the +5v rail. What voltage are you seeing at the regulator input and output (pin 1 input, 2 GND, 3 output)?
BFixing 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…
... rail. What voltage are you seeing at the regulator input and output ...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…
... RAM is (currently) good.
Can you also measure the voltage ... put out too high a voltage which kills the oscillation circuit ...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…
... RAM is (currently) good.
Can you also measure the voltage ... put out too high a voltage which kills the oscillation circuit ...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…
The internal switching regulator circuit in 16k/48k Spectrums ... correctly when the loaded input voltage was 12V or higher.
voltage. Don't forget to measure ...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…
... =1024MAK;776199]The internal switching regulator circuit in 16k/48k Spectrums ... correctly when the loaded input voltage was 12V or higher.
voltage. Don't forget to measure ...New Spectrum User - Inveterate UpgraderI've been asking a few questions about my Speccy, which is the first I've owned despite my advancingh years. I was a C64 kid, but please don't hold …
... failure kills the +12v/-5v voltage conversion circuitry, which is particularly ... fatal for the lower ram (4116) which depends on +5v ... sometimes induce failure of this voltage conversion circuitry, the received wisdom ...AAAARRRRR DIV-MMC ENJOY againIve recently been posting trying to get to the bottom of problems with my +48 not working with this rechid addon.Now ive finaly worked out theres not…
... TR4 and TR5 for the RAM memory. So the loss of ... these supplies cannot kill the RAM (unlike 16k and 48k machines ... about the health of you RAM... But if you can enter ... , this comes from the 7805 regulator (or 78S05).
And ...Spectrum 128 malfunctioning with DIVMMCI recently got myself a spectrum 128 (toastrack) and a DIVMMC card so I could load games from it. It all works fine until it has warmed up and then t…
... practically no heat, but the regulator in Toastrack is rated above ... .96A@10V with the original regulator and 0.60A@10V with ... power supplies, since the output voltage of it increased too much ...Ben Heck modifies a Zee X Spectrum.Gahh, one of the differences between Americans and Europeans right there in the title. Anyway, we know better ;) ...and this isn't about that anyway.…
... c64 and atari.. the NTSC / voltage thing makes it a bit ... " the idea of the low ram replacement from someone here who ...Creating real usable custom romsWhat is needed and what would the cost be to create a custom rom for a +128 or +2 I only ask because ive been messing around under emulation with som…
... it can't test multi-voltage chips like our 4116 friends ... and writing eproms, and testing RAM!Creating real usable custom romsWhat is needed and what would the cost be to create a custom rom for a +128 or +2 I only ask because ive been messing around under emulation with som…
... it can't test multi-voltage chips like our 4116 friends ... and writing eproms, and testing RAM![/QUOTE]
I used Wellon ...Toastrack refurbishmentYesterday I opened a drawer in my old desk and discovered 2 complete toastrack 128s and a board only for the same. As I already have a fully working…
... ;780970]With the 7805 regulator switching replacements there's ... current, the regulator will reduce the output voltage until the current ... this behaviour and then the regulator could overheat.
regulator. They do survive :-). ...Help me fix my grail ZX 128k SpectrumHi all, Ok today my grail toaster rack ZX spectrum 128k turned up. I finally found one and for a reasonable price. I powered it up and..... Nothing …
... . No voltage on the 5v rail would either indicate a regulator failure ... from the motherboard to the regulator on the heatsink is attached ... checks out, try replacing the regulator with a 7805 or 78S05 ...Help me fix my grail ZX 128k SpectrumHi all, Ok today my grail toaster rack ZX spectrum 128k turned up. I finally found one and for a reasonable price. I powered it up and..... Nothing …
... middle pin and check the voltage on pin 1 (left), this ... what you see, then the regulator is fine.
Try ...Help me fix my grail ZX 128k SpectrumHi all, Ok today my grail toaster rack ZX spectrum 128k turned up. I finally found one and for a reasonable price. I powered it up and..... Nothing …
... voltage do you get on the lead connected to the 7805 regulator ... pin 1 (the input)?
What voltage do you ... get on the lead connected to the 7805 regulator ...Help me fix my grail ZX 128k SpectrumHi all, Ok today my grail toaster rack ZX spectrum 128k turned up. I finally found one and for a reasonable price. I powered it up and..... Nothing …
Use the 20V DC voltage range on the top left of the selection switch.
Then test pin 1 and pin 3 of the regulator again...ZX Spectrum 48K AV IssueOK so I dugout my old 48K Speccy today and decided to AV mod it. I did the mod (pretty easy) but the picture I am getting is this. [url=http://posti…
... a failure of the onboard voltage conversion circuitry - are you sure ... or more of the lower RAM IC's have failed (IC6 ...ZX Spectrum 48K AV IssueOK so I dugout my old 48K Speccy today and decided to AV mod it. I did the mod (pretty easy) but the picture I am getting is this. [url=http://posti…
Ok, so the voltage conversion circuitry isn't working. < ... missing or non-functional lower RAM, which you'll get without ... checks fail, remove the 4116 RAM one by one until the ...ZX Spectrum 48K AV IssueOK so I dugout my old 48K Speccy today and decided to AV mod it. I did the mod (pretty easy) but the picture I am getting is this. [url=http://posti…
... black lead to 0V (the regulator tab or the heatsink will ... charge up from the small voltage from the meter).
New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... about trying a ROM based RAM tester. You need a ... a ROM cartridge with a RAM testing program on it. ... this? Well, often the RAM test can tell you how ... if a RAM chip is dragging down the voltage on a data ... do decide to desolder the RAM chips, practice on an ...ZX Spectrum 48K AV IssueOK so I dugout my old 48K Speccy today and decided to AV mod it. I did the mod (pretty easy) but the picture I am getting is this. [url=http://posti…
... to whip off the lower RAM, then replace TR4. (In my ... verify that you have all voltage rails back in the absence ...Burned finger temp on rubber 48k heatsink normal?Ok so i opened it up because a few keys started to act up and i noticed that after burning my hand the heatsink was that hot i could actually smell t…
... supply is at a higher voltage than is strictly necessary. There ... />
Reducing the power supply voltage (provided it is presently above ... /> Replacing the 7805 regulator with a switching regulator will completely cure the ...
